Constant flow pump



Jan. 26, 1943. M. c. CUTHBERT 2,309,443

CONSTANT FLOW PUMP Filed July l2, 1941 2 Shee'ts-Sheet l A5" I /11'611 tor Meriem C. z/er Jan. 26, 1943. M. c. CUTHBERT 2,309,443

CONSTANT FLOW PUMP Filed July l2, 1941 2 Sheets-Sheet 2 luren/or Patented Jan. 26, 1943.

ENCE

CONSTANT FLOW )P iur Merton C. Cuthbert, Jacksonville, Fla.

Application `uiy 12, 1941, Serial No. 402,212

l Claim.

My invention relates to improvements in noncompressible uid pumping means, and in particular to constant flow series rotary pumping means, wherein the back flow is substantially reduced and staggered inoccurrence, so that the outow is substantially constant, and the primary object of my invention is to provide a simple and efficient arrangement of this character.

Other important objects and advantages of my invention will be apparent from a reading of the following description taken in connection with the appended drawings, wherein for purposes of illustration I have shown a preferred embodiment of my invention.

`In the drawings- Figure l is a side elevational view of the ernbodiment.

Figure 2 is a top plan view of Figure 1.

Figure 3 is a side elevational view with the side plate removed.

Figure 4 is a'perspective view of one of the rotary gates.

Figure 5 is a perspective view of one of the rotary pistons.

Referring in detail to the drawings, the numeral 5 generally designates the pumping elements 6 and '1, respectively, each of which comprises an aligned pair of substantially two-third cylindrical chambers 8 and 9, respectively, at

lthe center of which are respective shafts I0 and II, which have outside gears I2 and I 3 in mesh, the shafts I I of the two pumping elements being connected together by a sprocket chain IB trained over sprocket wheels I5 as indicated in Figure I of the drawings whereby the two pumping elements are operated together and in phase..

A removable side plate IS held in place by bolts Il exposes the chambers 8 andfS as indicated in Figure 3 of the drawings. The two pumping elements are connected by a web or standard IB which rises from a base I9, and the upper and lower chambers 8 and 9 in each unit are connected in communication by a horizontal passage which has a middle portion 2l which establishes communication between the adjacent sides of the chambers of the two pumping units 6 and 'I. The left hand end of the passage 20 is the outflow or discharge of the pumping unit while the right hand end of the passage 20 is the intake.

Keyed on the upper shafts I0 are hourglass gates 22 and 22', while keyed on the lower shafts II are the pistons 23 and 23', respectively. The pistons 23 comprise relatively small diameter circular portions 2i which are concentrically mounted on the shafts II and from the opposite sides of which radiate diametrically opposed arms 25 and 25', the outer ends of which run close to the peripheral walls of the chambers 9 and extend into the passage 20 as indicated in Figure 3 of the drawings.

The rotary gates 22 and 22' comprise the central parallel sided portion 26 from the opposite ends of which radiate the segmental portions 21, with the peripheral edges of the segmental portions running close to the lperipheral wall of the chambers 8, and to the periphery of the circular portions 2d of the pistons 23 and 23.

As indicated in Figure 3 of the drawings the pistons and the rotary gates are arranged on their shafts a quarter revolution apart, so that in the position shown in the left hand unit E the maximum size of outow opening is defined between the piston 2t and the rotary gate 22, so that substantially no restriction is offered to the outflow of the uid through the passage 20. In similar phase the outow is similarly unrestricted from the unit 'I into the unit 6.

It will be observedthat in the cases of most rotary pumps there is a great defect in that at some point in the cycle the outflow is greatly restricted with a consequent large loss of energy when-the pump is operated at high speed. In the present invention the greatly enlarged size of the outflow opening substantially prevents back iiow at this point, so that the uid under pressure is freely expelled. The emciency oi' the pump is further aided by the fact that the pressure on both sides of the recess is at all times equal, with the result that substantially no aid is required to drive the rotors, once the pumping unit has been primed and brought up to operating speed. In the present arrangement, as shown in Figure 3 of the drawings, the positions of the rotors, besides being one-quarter of a turn ahead in the case of each pumping element, are arranged in substantially opposite phase and also at a 'quarter revolution out of phase, so that in the emitting stage the gates and pistons positively prevent back flow from one pumping element to the other.

Although I have shown and described herein a preferred embodiment of my invention, it is to be definitely understood that I do not wish to limit the application of the invention thereto except as may be required by the scope of the subjoined claim.

Having described the invention, what is claimed as new is:

A pumping device comprising a housing having a straight ow passage passing therethrough and said housing having a pair of gate chambers therein located to one side of the passage and a, pair of piston chambers therein located at the opposite side of the passage, all of said chambers being in communication with the passage with each gate chamber being placed opposite a piston chamber, a rotary gate in each gate chamber of hour-glass form and including 

